Many instruments on the instrument panel of a vehicle today are designed to be installed as a module with a simple slip-in fit wherein the module can be installed securely and aligned properly by simply pushing it into the instrument panel. Some type of bracket or clips will automatically lock the particular module into place without having to reach behind the panel to secure the module, and without requiring any tools to install it. Many of these instrument modules are also removable from the front, again without the need to remove brackets or screws from behind the panel to remove the unit from its support, by using a simple removal tool that merely slides through some holes in the front of the module and disengages the bracket or clip from the instrument panel.
One such design uses a pair of simple spring clips, one each mounted on the sides of the instrument module, just behind a front bezel of the module. An example of such a design is disclosed in U.S. Pat. No. 4,550,944 to Simon et al., incorporated herein by reference. Each clip has a pair of retention fingers with corresponding barbs that secure and align the module in the instrument panel. The fingers are connected to a base portion at their rear end. The base portion fastens to the module. The fingers either angle away from the side of the module protruding more as they extend toward the bezel, with the barbs on the front end of the fingers that catch on the back side of the instrument panel; or the fingers run parallel with the side of the module and the barbs themselves protrude outward at the front end of the fingers to catch on the instrument panel.
Also, each of these spring clips includes a pair of extraction ramps, each ramp connected to a corresponding finger. The extraction ramps align with associated holes through the front of the module bezel, which accept an extracting tool. A portion of the extracting tool slides up on the ramps, which causes the ramps to pull the fingers, and consequently the barbs, toward the side of the module, away from the back of the instrument panel. This allows the module to be slid out of the instrument panel.
The retention fingers of these spring clips are under a constant stress due to deflection caused by contact with the back of the instrument panel while the module is installed. The corresponding spring force, due to stress, assures that the module stays aligned and secure. What these particular prior art spring clips lack is a secondary back-up securing and aligning mechanism. Preferably one that is under less stress, and hence, less fatigue, to insure there is always a back-up or secondary system at the ready. This way there would be no reduction in the maximum force the clip could withstand during a rear vehicle impact or a forced removal.
The difficulty with creating this back-up system is that the module should still be easily and quickly installed and removed from the front of the instrument panel by simply sliding it in and out. Also, it is desirable to accomplish this with a similar simple tool as is currently used with these types of clips. Further, it is desirable to fabricate the bracket inexpensively, from a single piece of material, and maintain the lightweight characteristics of current spring clips.
Additionally, some instrument modules, such as radios, are becoming larger due to added features and, as a result, need more support. However, one will not want to add to the cost and weight of retaining the radios, nor reduce the simplicity of installation and removal. The trend toward heavier radios makes a robust spring clip design desirable to assure sufficient support to meet any rear collision or forced removal radio retention needs.